Crosslinked polymers which are insoluble in water, but are capable of absorbing large amounts of water are known in the art and are used for instance in disposable diapers, sanitary napkins and tampons as well as being used as horticultural and agricultural aids. U.S. Pat. Nos. 3,997,484, 3,669,103 and 3,670,731 for instance describe such polymers and their uses.
U.S. Pat. No. 3,448,088 describes water soluble crosslinked interpolymers which are useful as viscosity improvers.